Factorio Forums

Ok, I'm pretty sure this is a bug by now. I am too lazy to describe it again so I'll link my older post.
https://forums.factorio.com/forum/vie ... =25&t=9253

Have a look at this bug post: https://forums.factorio.com/forum/vie ... =23&t=9297
Maybe it's similar to what you're seeing?

Entity.energy for burner type energy sources is not directly supported. You can set it but the capacity of the entity's energy is dynamically set based off what it's burning.

That means you need to set entity.energy each tick if you want to use it. Otherwise use an electric energy source and define a buffer size in the prototype - that will allow you to set the energy up to a maximum of the buffer size.

Oh I didn't realize that there was already a post about that. Guess I'll search the bug reports first next time. It kinda annoys me that it works like that though. I don't like those hack-arounds that I have to use now...